Molecular components and dynamics of the osmoregulatory system Paramecium tetraurelia

草履虫细胞具有渗透调节系统(ORS)，其H+-ATPase产生质子梯度，通过化学渗透隔离，允许有节奏地排出水分。这与某些离子的选择性挤出是平行的，例如，钙离子。ORS活性确实是维持钙离子停滞的主要成分，它含有一种用于微调钙离子的InsP3受体。除了H+-ATPase的一组复杂的亚单位(位于更外围的海绵体)，我们在草履虫基因组计划的框架内发现了一组ORS特异的陷阱(主要在光滑的海绵体)，我们可以用几个热点将SNARE特异性伴侣NSF定位到ORS。由于圈套被认为与特定的膜相互作用和融合有关，因此问题出现了，它们是否以及如何对这种复杂细胞器的生物发生起到了迄今未知的作用。在ORS的节律性搏动活动中，SNARS不仅可能介导膜相互作用，而且在理论上，SNARS-PINS还可以在海绵体内建立平行管状结构的复杂分支。我们打算分析复杂的分子相互作用，包括。阳离子交换器和水通道蛋白，参与草履虫的生物发生和ORS功能的执行。

Paramecium cells possess an osmoregulatory system (ORS) whose H+-ATPase produces a proton gradient which in turn, by chemiosmotic sequestration, allows the rhythmic expulsion of water. This is paralleled by the selective extrusion of some ions, e.g., Ca2+. ORS activity is indeed the dominating component to maintain Ca2+ hoemostasis and that it contains an InsP3 receptor for Ca2+ fine-tuning. In addition to a complex set of subunits of the H+-ATPase (located in the more peripheral ¿decorated spongiome¿) we found, within the frame of the Paramecium genome project, an ORS-specific set of SNAREs (mainly in the ¿smooth spongiome¿) and we could localize, with several hot spots, the SNARE-specific chaperone, NSF, to the ORS. Since SNAREs are considered relevant for specific membrane interactions and fusion the question arises whether and how they contribute to the as yet unknown biogenesis of this complex organelle. SNAREs may mediate not only membrane interactions during the rhythmic pulsation activities of the ORS, but SNARE-pins could theoretically also establish the complicated branching of parallel tubular structures in the spongiome. We intend to analyze the complex molecular interactions, incl. cation exchangers and aquaporins, involved in biogenesis and performance of the ORS function in Paramecium.